profuse/Device/DiskCopy42Image.cpp

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#include <cstdio>
#include <cstring>
#include <algorithm>
#include <Device/DiskCopy42Image.h>
#include <Endian/Endian.h>
#include <Endian/IOBuffer.h>
#include <Cache/MappedBlockCache.h>
using namespace Device;
using namespace BigEndian;
using ProFUSE::Exception;
using ProFUSE::POSIXException;
enum {
oDataSize = 64,
oDataChecksum = 72,
oPrivate = 82,
oUserData = 84
};
DiskCopy42Image::DiskCopy42Image(MappedFile *f) :
DiskImage(f),
_changed(false)
{
setAdaptor(new POAdaptor(oUserData + (uint8_t *)address()));
setBlocks(Read32(address(), oDataSize) / 512);
}
DiskCopy42Image::~DiskCopy42Image()
{
if (_changed)
{
MappedFile *f = file();
if (f)
{
void *data = f->address();
uint32_t cs = Checksum(oUserData + (uint8_t *)data, Read32(data, oDataSize));
Write32(data, oDataChecksum, cs);
f->sync();
}
// TODO -- checksum
}
}
uint32_t DiskCopy42Image::Checksum(void *data, size_t size)
{
uint32_t rv = 0;
uint8_t *dp = (uint8_t *)data;
if (size & 0x01) return rv;
for (size_t i = 0; i < size; i += 2)
{
rv += dp[i] << 8;
rv += dp[i+1];
rv = (rv >> 1) + (rv << 31);
}
return rv;
}
BlockDevicePointer DiskCopy42Image::Open(MappedFile *f)
{
Validate(f);
//return BlockDevicePointer(new DiskCopy42Image(f));
return MAKE_SHARED(DiskCopy42Image, f);
}
static uint8_t DiskFormat(size_t blocks)
{
switch (blocks)
{
case 800: return 0;
case 1600: return 1;
case 1440: return 2;
case 2880: return 3;
default: return 0xff;
}
}
static uint8_t FormatByte(size_t blocks)
{
switch(blocks)
{
case 800: return 0x12;
default: return 0x22;
}
}
BlockDevicePointer DiskCopy42Image::Create(const char *name, size_t blocks)
{
return Create(name, blocks, "Untitled");
}
BlockDevicePointer DiskCopy42Image::Create(const char *name, size_t blocks, const char *vname)
{
MappedFile *file = MappedFile::Create(name, blocks * 512 + oUserData);
uint8_t tmp[oUserData];
IOBuffer header(tmp, oUserData);
// name -- 64byte pstring.
if (vname == NULL) vname = "Untitled";
unsigned l = std::strlen(vname);
header.write8(std::min(l, 63u));
header.writeBytes(vname, std::min(l, 63u));
//header.resize(64);
header.setOffset(oDataSize, true);
// data size -- number of bytes
header.write32(blocks * 512);
// tag size
header.write32(0);
// data checksum
// if data is 0, will be 0.
//header.push32be(Checksum(file->fileData(), blocks * 512));
header.write32(0);
// tag checksum
header.write32(0);
// disk format.
/*
* 0 = 400k
* 1 = 800k
* 2 = 720k
* 3 = 1440k
* 0xff = other
*/
header.write8(DiskFormat(blocks));
// formatbyte
/*
* 0x12 = 400k
* 0x22 = >400k mac
* 0x24 = 800k appleII
*/
header.write8(FormatByte(blocks));
// private
header.write16(0x100);
std::memcpy(file->address(), header.buffer(), oUserData);
file->sync();
//return BlockDevicePointer(new DiskCopy42Image(file));
return MAKE_SHARED(DiskCopy42Image, file);
}
bool DiskCopy42Image::Validate(MappedFile *file, const std::nothrow_t &)
{
#undef __METHOD__
#define __METHOD__ "DiskCopy42Image::Validate"
size_t bytes = 0;
size_t size = file->length();
const void *data = file->address();
uint32_t checksum = 0;
if (size < oUserData)
return false;
// name must be < 64
if (Read8(data, 0) > 63)
return false;
if (Read16(data, oPrivate) != 0x100)
return false;
// bytes, not blocks.
bytes = Read32(data, oDataSize);
if (bytes % 512)
return false;
if (size < oUserData + bytes)
return false;
// todo -- checksum.
checksum = Read32(data, oDataChecksum);
uint32_t cs = Checksum(oUserData + (uint8_t *)data, bytes);
if (cs != checksum)
{
fprintf(stderr, __METHOD__ ": Warning: checksum invalid.\n");
}
return true;
}
bool DiskCopy42Image::Validate(MappedFile *file)
{
#undef __METHOD__
#define __METHOD__ "DiskCopy42Image::Validate"
if (!Validate(file, std::nothrow))
throw Exception(__METHOD__ ": Invalid file format.");
return true;
}
void DiskCopy42Image::write(unsigned block, const void *bp)
{
DiskImage::write(block, bp);
_changed = true;
}
BlockCachePointer DiskCopy42Image::createBlockCache()
{
// if not readonly, mark changed so crc will be updated at close.
if (!readOnly()) _changed = true;
return MappedBlockCache::Create(shared_from_this(), address());
}